Customizing Fiber-Optic Links - AT&T System 85 Installation And Test

CUSTOMIZING FIBER-OPTIC LINKS
After the RMI hardware is installed and the cabling is completed at both the central and
remote locations, test the fiber-optic links. Adjust the fiber link if necessary, to achieve the
required power levels. Each fiber link must be tested individually.
Adjust the fiber-optic link as follows:
1. Set the switch settings on the transmitter paddleboard (Z982C or Z982J, Figure 44) to
the TEST mode.
Note: If transmitter is not in test mode, the LEDs on the receiver will not give
valid information. The LEDs should be ignored when the transmitter paddleboard
is in the normal mode.
2. Set the power switch on the transmitter paddleboard to FULL or HALF based on
distance between central and remote locations (Table AK).
3. Determine the condition of the fiber-optic link by observing the LEDs on the receiver
paddleboard (Z982D). These conditions are:
a. If one green LED lights, the link is within the required power range.
b. If both LEDs are red, the link is in an overdriven condition.
c. If a single LED is red, the link is in an underdriven condition.
4. To adjust the fiber-optic link if underdriven or overdriven, adjust the link components
necessary to achieve the required power level (Table AK, Figure 72). These adjustments
include:
a. Changing power level settings on transmitter paddleboard to HALF/FULL
power
b. Replacing 401-series attenuator at LCIT with one of different value.
5. Repeat Step 4 until link is within required power range.
6. Return the switch settings on the transmitter paddleboard (Z982C or Z9821) to the
NORMAL mode.
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